$ { \left[\begin{array}{rr}{1} & {-1} \\ {3} & {1} \\ {4} & {2}\end{array}\right]+\left[\begin{array}{rr}{4} & {-1} \\ {4} & {-1} \\ {1} & {2}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{1}+{4} & {-1}+{-1} \\ {3}+{4} & {1}+{-1} \\ {4}+{1} & {2}+{2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{5} & {-2} \\ {7} & {0} \\ {5} & {4}\end{array}\right]}$